i've tripped in a lot of different situations, and honestly, i found the most enjoyable was to be with a close friend, not a significant other. although i guess a lot of my s/o's have been uninterested in psychedelics, even if they used to do them, so doing it around them was...not as fun as if we were both tripping around.
i tripped once with my boyfriend of nearly two years (it was his first time in as many years), and while it was fun, for some reason i didn't enjoy it as much as when i was with close friends.
in the last year or so though i've cut down a lot on tripping. i find that i'm more apt to get stuck in memory loops and while my trips aren't bad, they don't have the same joy to them that they used to. i've gotten very particular about who i trip around, when, and where.