is it wrong from my bf to sleep in the same bed as our girl friend

*LONG STORY* so after New Year's <a href="">Eve</a> party, my boyfriend, his younger bro and his older sis all slept at his brother's girlfriend's house. (she lives by herself), cause they were all drunk and couldn't drive home obviously (my bf lives about 45mins away from where the party took place). and I forgot, one of our girl friends slept there with them also. So the next day (january 1st), i asked my bf (on text) where Sarah (our girl friend) slept (to make sure she didnt sneak next to my bf to sleep next to himcause she was sooo drunk). he told me that she slept in the kitchen in a sleeping bag. I trust my boyfriend a lot and know he wouldn't have the guts to get too close with another girl. and today, he admitted to me in person that he had lied to me about where Sarah slept, and he told me they shared a  bed or a matress on the floor idk, but yeah they slept next to each other. i mean idk if they did that cause there wasn't enough beds for everybody in the little appartment but yeah. he slept in the same bed as her, but swore and promised to me they didn't do anything (i mean his siblings were there so i believe its true). but should I be mad that my bf slept in the same bed as our girl friend, even tho they didn't do anything at all except sleeping? I'm mostly hurt and upset because he lied to me but he told me, at least.