The first time I ever tripped (truffles) was together with my (then very recent) girlfriend.
She ended up taking a threshold dose though while I took a bit more. In retrospect the setting wasn't super ideal since we were with a few non-tripping friends (though we felt very comfortable with them), and while my gf didn't experience any adverse effects, it didn't seem to leave the lasting impression on her the way it did for me. She said she enjoyed the experience but was not going to do it again since she feels like she is too "mentally unstable" in her own eyes and doesn't want to risk a bad trip. That's cool by me, these substances aren't for everyone and I'm not going to try and convince her otherwise. Ever since I have mostly tripped solo a good handful amount of times every year (sometimes with likeminded friends as well, though more rarely), and she remains very understanding of my relationship with psychedelics, so I guess I can already consider myself very lucky in that respect.
She is still not entirely down with me taking LSD, entirely because of the microgram dosage. I am still trying to convince her that I am careful and responsible, that I test my stuff and that LSD is physically harmless, but she's not entirely convinced yet.. I really hope I can ease her mind on this soon. Also she didn't initially like the DMT extractions, which I can perfectly understand. I have done many months of reading since I'm into this subject matter while she knows just as much about it as the average person, so I can imagine what must have gone through her head when I first asked her if she would be okay with that. She can live with it, but in the back of my mind I sometimes wonder how crazy or obsessed she really thinks I am
She's a daily weed smoker though, is into (classic) rock and metal and open-minded in terms of the benefits of weed, psychedelics and mdma, just to note she is not entirely conservative
"The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion." - Albert Camus