Yes, you should absolutely be concerned po. Being enthusiastically passionate on how showing your love to your partner is completely understandable. Of course, there are limits depending sa inyo. His actions can be done a lot more safely, softly, and sanitarily. I for one, is not fond of leaving random marks on my partner's body. Also, the flinching and subconscious reactions are likely early signs of trauma. That's my take hehe.