YK Osiris Accused of Sexual Assault for Forcing Kiss on Sukihana

YK Osiris believed he had the right to grab Sukihana and plant an unwanted kiss on her lips, and for that, the internet is letting him have it ... accusing the singer of sexual assault.

The whole thing went down over the weekend at The Crew League event in ATL. Suki's sitting at the host table when Osiris comes up behind her and starts to rub her bare shoulders.

Suki appears uncomfortable -- but then YK ramps it up, grabbing her face and attempting to kiss her. Suki successfully avoids his first attempt, but then he does it again as she yells out ... this time planting one directly on her lips.

After the incident, YK seemingly oblivious to how awkward the whole thing looked, laughs it off -- apparently thinking what he did was funny.

Sukihana appeared stunned as YK walked away, but later tweeted, "I drink to hide that I'm very sensitive. I feel things more then the average person. I stopped drinking yesterday but today I've been crying all day. I asked God to strengthen me and use me to help others and to order my steps in his word. I just want to go away for awhile."

Sources familiar with what went down tell us Suki doesn't even know YK, and they don't have any sort of relationship. We're told Suki didn't want to make a big scene when it happened, and tried to stay professional ... but the whole thing was disturbing to her.

YK has not yet addressed the incident.