worried about best friend liking my fiancé

Okay so I feel like my best friend is trying to get with my fiancé she constantly talks about how hot he is and how I'm the luckiest girl she knows my boyfriend constantly assures me that I have nothing to worry about but yesterday we were all having lunch together and she and him were laughing about something I've never even heard about and she kept touching his shoulder and it just made my blood boil and I know she's my best friend but please tell me I'm not overreacting picture is me and my fiancé on our recent camping trip he loves me I promise