Does Pervert Elizabeth have a lot of skimpy outfits to dress Meliodas up in? Could the skimpy clothes Meliodas had for Elizabeth Liones form way back in season 1 when they first talked about her being a waitress at the bar be his own form of revenge form how she’d force him into skimpy clothes? Does he have matching sets from back during the war hidden a closet somewhere?
She really might, honestly, but the fact that he dressed her up in them right after they met implies that she didn't dress him up that often. Not often enough for him to think it would trigger her memories at least.
And yes, it absolutely could've been his own personal revenge. He probably reacted in much the same way that she reacted in the Boar Hat.
And I wouldn't put it beyond him to have kept the skimpy outfits. Elizabeth made them (or had them made) for him after all, and even though their main purpose was to fulfill Elis perverted desires, he could tell that she put effort into making them comfortable to wear for him (not counting that they barely hid anything). The outfits didn't chafe anywhere and didn't get in the way of his daily business, so practically speaking, he could've worn those outfits as his everyday clothes. His goddess is a huge pervert, but a pervert with love.
And if he kept the matching outfits hidden, that means Eli can find them, and if she finds them, she will absolutely want to dress in matching outfits with Mel. Hawk is mortified upon learning about his additional side of Elis perversion that knows no bounds. He also asks Mel why he kept them if they were so embarrassing to wear, and Mel just blushed a deep red and said 'no reason', but was very obviously lying.