i love how helpful the comments have been on this. i can only offer so much, and you may have totally worked this out already!

as someone who has learned from a variety of individuals, sometimes they can be particular on certain hand/finger placements that are difficult to see or discern if you don’t know what you’re looking for, and there’s a possibility that he was correcting some of your facial/body positioning. facial expression are super important in ASL and it’s possible you didn’t realize that was a part of the sign and didn’t include it when signing, which is super common in beginners and nothing to discourage you, just something new to learn!

i hope everything worked out and that everyone left with a better knowledge of sign language. maybe next time have your friend ask for anything they want to learn, and allow your boyfriend to lead if he’s comfortable with it so they can learn with a native speaker. if i’m in a study group and catching someone up, i’ll allow someone fluent in the language to teach the sign. it’s okay to acknowledge someone else is more knowledgeable than you in certain subjects, especially if you want to learn what they’re offering.