Belev Echad, some people (mourners) attend weddings of close friends and family and sit outside at a table designated for them.
I’m not really that strict with many things but for some reason, when my dad died, I felt guilty not keeping the halachot. I didn’t dance by a close friend’s wedding which was HUGE for me (I’m a dancer…)
I don’t know if heterim are easy to get, but you could always ask a Rabbi if you want to do the right thing.