Lady Gaga pulled double duty as host and musical guest of 'SNL' last night (Nov. 16) and for her first of two performances, she donned a sparkly, silver, low-dipping jumpsuit to perform 'Do What U Want,' her sexy R&B romp with R. Kelly. She gyrated onstage in overtly sexual fashion and had us wondering how she would handle R.'s parts ... until R. himself joined her onstage for his verse and a little dry humping action.

It was NOT PG-rated.

Gaga and R. got down, simulating sex, with Ma Monster wrapping her legs around him as he held her up as she sang. R. threw Gaga over his shoulder and whipped her around like a rag doll, but the kicker of all this dripping-with-sex physicality?

When Gaga was on her back and R. was on top of her, doing pushups over her! That R. really as some stamina.

He sure was looking dapper in his white suit.

The perf was a sexy and suggestive and for a hot sec, we had to stop and ask ourselves if Gaga and the R&B crooner had a little somethin' somethin' going on. Their chemistry was that scorching, and this live rendition of their 'ARTPOP' track crackled.

Gaga later returned to perform 'Gypsy,' seated at a pink piano and wearing wings, reminding us that she is a true visual artist, too.

She was eventually joined by a dancer, guitarists and even appeared to play guitar herself. TBH, it looked like a prop. The vocals and timing were off, likely because she used a backing track. But regardless, nothing she did or performed could top that bump and grind act with Kelly.

Watch Lady Perform 'Gypsy' on 'SNL'