The Flash's Grant Gustin Bares His Butt While Skinny Dipping!

Grant Gustin is showing off a lot of skin while enjoying a vacation in Mexico with wife LA Thoma!

The 29-year-old The Flash actor put his butt on display while going skinny-dipping in a private pool at their hotel, Las Ventanas al Paraiso.

“Sad to leave it behind,” Grant captioned the photo on his Instagram account.

Grant‘s former Glee co-star Kevin McHale commented, “Thank you.”

Robbie Amell, who has appeared on The Flash, commented on the photo and said, “New phone background.”

It sure looks like Grant had a great time on his vacation!

Click inside to see the photo of Grant Gustin’s bum…