Bianca Censori Wears See-Through Top, Grabs Ice Cream with Kanye West

Bianca Censori knows how to cool off a hot day ... grabbing ice cream with her man Kanye West -- and wearing her skimpiest clothes out.

The two stars were spotted in Mallorca with Bianca's sister, Angelina ... stopping off for a sweet treat in a crowded marketplace -- and Bianca's back in her summer ensembles, leaving nothing to the imagination.

BC wore a mesh top out with no bra underneath -- so, everyone around them got to see everything she's packing up top.

As for her bottoms ... the front's a long skirt, giving some coverage to her down stairs -- but, she's basically just wearing booty shorts, and her backside's definitely not contained.

Kanye's dressed a bit more conservatively ... a gray sweater with "Army" written in black letters across the front and dark sunglasses on his face -- though he's not covering up with a full mask or bandana like we've seen him in the past.

It's a rare sighting for the couple ... whose relationship was in trouble back in February. Remember, shortly after the Grammys stunt -- where Bianca showed up in a body suit that covered basically none of her body -- sources told us both Kanye and Bianca reached out to divorce attorneys.

We were told they have no prenup ... which would've made for a messy divorce -- but, then they were spotted in Mallorca -- which has become their Spanish sanctuary -- last month grabbing dinner together.