Is it okay to use another player's character 'fantasia' as your own without asking?

[Suki-]

I'd find it tacky if they actually copied a friend or another FC member otherwise I'd say go for it if you like the look.

Had this happen to myself, person from a previous fc just stood there in silence targeting me while I was doing... something, I forget what. 5 minutes later they fantasia into an almost exact replica, hair style/colour and all. Only eye colour was different.

Was. Not. Impressed.