Tekashi 6ix9ine  celebrated his girlfriend Aliday Alter 's pregnancy at their gender reveal party Friday ... but according to him, he only planned to celebrate if they were having a boy! Check out a clip from his livestream from the shindig -- he tells pals Clavicular , N3ON , and Adin Ross he only wants a son ... and if the gender results show a baby girl -- they're heading to the abortion clinic. The group of streamers was noticeably shocked and seemingly tried to play it off as a joke, but