Women and guy friends?

Do any of you girls or women have guy friends who go with you to festivals (2 days) or trips without anything sexual happening, just friends?

CONTEXT:

I am 35M and I am dating for 3 months 31F. We like each other, I meet her parents (for other reasons – bad history, they just want to make sure she is safe) and friends. She also posted me on IG and story so her people know briefly who I am. About 20 days ago, she told me she is not used to having a guy in her life (as a boyfriend) and suggested that we go slowly. I agreed. 10 days ago in some light panic attack (hers), she asked me if I want a serious relationship with her now. I told her that I would really like to go slowly and see where things go and I told her that I am exclusive to her and I am interested only in her. The reason I want to go slowly is that she has some problems of her own and I don’t want to promise something lasting, but just have fun, be exclusive and get to know her more, slowly.

We miss each other and see each other every weekend and spend time together. But now when I ask if she comes on Friday she told me she is going to a festival with her guy friend (2 days). And sure I ask her about it because I got a bit jealous. She told me not to worry because nothing will happen. She knows this friend for 10 years and she told me that there was nothing between them. I really am jealous…I care for her, I got cheated in this way in the past. Do you women have such good friends to go with them and are both single (man single, female exclusive)? I am super worried