The fabric triangle on the back of a thong, connecting the waist bands to the ass band. Usually seen when a female wearing a thong bends over and the thong peeps out from her low rise jeans.
Check out Tina's t square, looks like she wearing her pink bedazzled panties again.
A sexual position where the penetrating partner lays on their side perpendicular with the receiving partner. The reciving partner lays on their back draping their legs over the penitrating partners side. The resulting formation looks like an architectural T-Square
"Hey babe you want to mix things up and try the t square this time?"