I looks fine to me. I wouldn't worry about it. Keeping wearing what makes you comfortable.
As a teacher, it's good to wear what makes one comfortable but if ever an admin have to speak to you, you know someone, usually parents or a jealous collegue has brought it to the attention of the principal, or VP, even board. Of course there may be a dress code that you have to follow. Just be prudent and unless you get off with your ego being "stroked" like this than it's your call whether to defend your cock showing through the clothes you wear or not. Going commando would be for me not an option. Hey there's no defense except your desk. If you have provocative student in class watch out, their game is to get that bulge bulging! And watchout for those phone cameras, that's proof for them. And I think you know what I mean.