Tristan Thompson Alleged NYC Chick Posts Sex Tape

8:40 AM PT -- Multiple reports say the woman in NYC with Tristan is an IG model named Lani Blair. As for Ms. Stephaniee ... it appears she might have no involvement, and was merely trolling Tristan and Khloe.

A woman claiming she spent the night with Tristan Thompson in NYC this weekend posted and quickly deleted a sex tape and a number of raunchy text messages allegedly with the NBA All-Star.

The woman -- who goes by @ms.stephaniee_ on Instagram -- claims she's the one who was seen in a video Saturday night walking into the Manhattan Four Seasons with Tristan. Tuesday night she filled her IG story alleged texts from Tristan and a video of a couple having sex ... which she claims is her and Tristan. Neither of their faces is visible in the short clip.

One of the alleged texts from Tristan read, "If I was there I would grab u while u try to walk away from me than I would pull ya hair and kiss you than rip ya clothes off and lay u down while I suck ya p**** and say sorry."

TMZ broke the story ... Thompson was seen making out, touching and motorboating two women back in October at a hookah lounge in the Washington D.C. area.