Case of the Mondays? Here are the Houston Texans cheerleaders partyin' in bikinis to make everything all better!!

The lovely ladies held their 1st Annual HTC Picnic Sunday ... full of chillin', grillin', volleyball killin', and of course, tons of photo ops with pool inflatables.

Seems like there's a friendly competition between HTC and the Dallas Cowboys cheerleaders for hottest squad in the NFL ... and we're here for it.

Trust us ... you're gonna want to check out all the hot pics from the epic pool party.

CHILLIN' AND GRILLIN'