Yes of course!
Although, I fear he would buy the wrong size...but he'd definitely pick a style I like.

I definitely would trust my man. He seems to do a good job of picking things that fit my body type well, and he knows all my sizes.

Yup, I trust him.

Totally. In fact my hubby does a better job a buying me clothes then I do! When we go shopping he's always finding things on the shelves and saying "try this, trust me it'll look great" I think it's because he spends so much time looking at my body he knows it better than I do

I wouldn't have any problems trusting a guy with buying lingerie. Only issue I would see is the same issues I face anytime I buy clothes, sizing. The shape of my body makes it hard and completely differently with every store, company, cut of clothing, etc. But with that issues I would just suggest to them to look for something that has one size fits most/all or plus size and go with plus size. I've only had one thing that was plus size that didn't fit (would hate to see how small "one size fits most" would have been!).

He has a great sense of style, so why not let him pick out lingerie?