diff --git a/Signal/Signal-Prefix.pch b/Signal/Signal-Prefix.pch
index 746c8e9e7..e9d10ecf2 100644
--- a/Signal/Signal-Prefix.pch
+++ b/Signal/Signal-Prefix.pch
@@ -20,5 +20,6 @@
     #import <SignalServiceKit/SSKAsserts.h>
     #import <SignalServiceKit/OWSAnalytics.h>
     #import <SignalServiceKit/NSArray+Functional.h>
+    #import <SignalServiceKit/NSSet+Functional.h>
     #import <SignalServiceKit/NSObject+Casting.h>
 #endif
diff --git a/SignalServiceKit/src/Loki/API/LokiAPI.swift b/SignalServiceKit/src/Loki/API/LokiAPI.swift
index b9055220a..aab06232a 100644
--- a/SignalServiceKit/src/Loki/API/LokiAPI.swift
+++ b/SignalServiceKit/src/Loki/API/LokiAPI.swift
@@ -52,6 +52,17 @@ public final class LokiAPI : NSObject {
             self.hexEncodedPublicKey = hexEncodedPublicKey
             self.objc_kind = kind
         }
+        
+        override public func isEqual(_ other: Any?) -> Bool {
+            guard let other = other as? Destination else { return false }
+            return hexEncodedPublicKey == other.hexEncodedPublicKey && kind == other.kind
+        }
+        
+        override public var hash: Int { // Override NSObject.hash and not Hashable.hashValue or Hashable.hash(into:)
+            return hexEncodedPublicKey.hashValue ^ kind.hashValue
+        }
+
+        override public var description: String { return "\(kind.rawValue)(\(hexEncodedPublicKey))" }
     }
     
     public typealias MessageListPromise = Promise<[SSKProtoEnvelope]>
diff --git a/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.h b/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.h
index bec1fd9ea..bffdfe76a 100644
--- a/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.h
+++ b/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.h
@@ -2,5 +2,6 @@
 @interface NSArray (Functional)
 
 - (NSArray *)filtered:(BOOL (^)(NSObject *))isIncluded;
+- (NSArray *)map:(NSObject *(^)(NSObject *))transform;
 
 @end
diff --git a/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.m b/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.m
index 296c041ee..309e33914 100644
--- a/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.m
+++ b/SignalServiceKit/src/Loki/Utilities/NSArray+Functional.m
@@ -12,4 +12,13 @@
     return result;
 }
 
+- (NSArray *)map:(NSObject *(^)(NSObject *))transform {
+    NSMutableArray *result = [NSMutableArray new];
+    for (NSObject *object in self) {
+        NSObject *transformedObject = transform(object);
+        [result addObject:transformedObject];
+    }
+    return result;
+}
+
 @end
diff --git a/SignalServiceKit/src/Loki/Utilities/NSSet+Functional.h b/SignalServiceKit/src/Loki/Utilities/NSSet+Functional.h
new file mode 100644
index 000000000..9808cc05f
--- /dev/null
+++ b/SignalServiceKit/src/Loki/Utilities/NSSet+Functional.h
@@ -0,0 +1,7 @@
+
+@interface NSSet (Functional)
+
+- (BOOL)contains:(BOOL (^)(NSObject *))predicate;
+- (NSSet *)filtered:(BOOL (^)(NSObject *))isIncluded;
+
+@end
diff --git a/SignalServiceKit/src/Loki/Utilities/NSSet+Functional.m b/SignalServiceKit/src/Loki/Utilities/NSSet+Functional.m
new file mode 100644
index 000000000..8d45bc498
--- /dev/null
+++ b/SignalServiceKit/src/Loki/Utilities/NSSet+Functional.m
@@ -0,0 +1,23 @@
+#import "NSSet+Functional.h"
+
+@implementation NSSet (Functional)
+
+-(BOOL)contains:(BOOL (^)(NSObject *))predicate {
+    for (NSObject *object in self) {
+        BOOL isPredicateSatisfied = predicate(object);
+        if (isPredicateSatisfied) { return YES; }
+    }
+    return NO;
+}
+
+- (NSSet *)filtered:(BOOL (^)(NSObject *))isIncluded {
+    NSMutableSet *result = [NSMutableSet new];
+    for (NSObject *object in self) {
+        if (isIncluded(object)) {
+            [result addObject:object];
+        }
+    }
+    return result;
+}
+
+@end
diff --git a/SignalServiceKit/src/Messages/OWSMessageSender.m b/SignalServiceKit/src/Messages/OWSMessageSender.m
index 03926c4b4..cd3698f46 100644
--- a/SignalServiceKit/src/Messages/OWSMessageSender.m
+++ b/SignalServiceKit/src/Messages/OWSMessageSender.m
@@ -901,6 +901,22 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
     return deviceMessages;
 }
 
+- (LKFriendRequestMessage *)getMultiDeviceFriendRequestMessageForHexEncodedPublicKey:(NSString *)hexEncodedPublicKey
+{
+    TSContactThread *thread = [TSContactThread getOrCreateThreadWithContactId:hexEncodedPublicKey];
+    return [[LKFriendRequestMessage alloc] initOutgoingMessageWithTimestamp:NSDate.ows_millisecondTimeStamp
+                                                  inThread:thread
+                                               messageBody:@"Test"
+                                             attachmentIds:[NSMutableArray new]
+                                          expiresInSeconds:0
+                                           expireStartedAt:0
+                                            isVoiceMessage:NO
+                                          groupMetaMessage:TSGroupMetaMessageUnspecified
+                                             quotedMessage:nil
+                                              contactShare:nil
+                                               linkPreview:nil];
+}
+
 - (void)sendMessageToRecipient:(OWSMessageSend *)messageSend
 {
     if (messageSend.thread.isGroupThread) {
@@ -914,16 +930,28 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
                 return [destination.kind isEqual:@"slave"];
             }];
             for (LKDestination *slaveDestination in slaveDestinations) {
-                OWSMessageSend *messageSendCopy = [messageSend copyWithDestination:slaveDestination];
-                [self sendMessage:messageSendCopy];
+                TSContactThread *thread = [TSContactThread getOrCreateThreadWithContactId:slaveDestination.hexEncodedPublicKey];
+                if (thread.isContactFriend) {
+                    OWSMessageSend *messageSendCopy = [messageSend copyWithDestination:slaveDestination];
+                    [self sendMessage:messageSendCopy];
+                } else {
+                    LKFriendRequestMessage *friendRequestMessage = [self getMultiDeviceFriendRequestMessageForHexEncodedPublicKey:slaveDestination.hexEncodedPublicKey];
+                    [self sendMessage:friendRequestMessage success:^{ } failure:^(NSError *error) { }];
+                }
             }
             LKDestination *masterDestination = [destinations filtered:^BOOL(NSObject *object) {
                 LKDestination *destination = [object as:LKDestination.class];
                 return [destination.kind isEqual:@"master"];
             }].firstObject;
             if (masterDestination != nil) {
-                OWSMessageSend *messageSendCopy = [messageSend copyWithDestination:masterDestination];
-                [self sendMessage:messageSendCopy];
+                TSContactThread *thread = [TSContactThread getOrCreateThreadWithContactId:masterDestination.hexEncodedPublicKey];
+                if (thread.isContactFriend) {
+                    OWSMessageSend *messageSendCopy = [messageSend copyWithDestination:masterDestination];
+                    [self sendMessage:messageSendCopy];
+                } else {
+                    LKFriendRequestMessage *friendRequestMessage = [self getMultiDeviceFriendRequestMessageForHexEncodedPublicKey:masterDestination.hexEncodedPublicKey];
+                    [self sendMessage:friendRequestMessage success:messageSend.success failure:messageSend.failure];
+                }
             }
         })
         .catchOn(OWSDispatch.sendingQueue, ^(NSError *error) {
diff --git a/SignalServiceKit/src/TSPrefix.h b/SignalServiceKit/src/TSPrefix.h
index a2445591c..fce828264 100644
--- a/SignalServiceKit/src/TSPrefix.h
+++ b/SignalServiceKit/src/TSPrefix.h
@@ -13,6 +13,7 @@ static const NSUInteger ddLogLevel = DDLogLevelInfo;
 #endif
 #import "OWSAnalytics.h"
 #import "NSArray+Functional.h"
+#import "NSSet+Functional.h"
 #import "NSObject+Casting.h"
 #import "SSKAsserts.h"
 #import "TSConstants.h"