Terra was a rather innocent individual, but her purity makes her very likable. She's a kind hearted girl and Selen couldn't imagine her not wanting to speak to Sephiroth again after his romantic approach, in which Selen would save the teasing for a bit longer. Though, she was surprised to see someone like him behave in such a manner but people are full of surprises.

He didn't really strike her as an impulsive person so she was confused. However, when an individual had strong feelings towards someone, it's hard to maintain your usual composure. It was perfectly understandable according to Selen's own logic. Selen felt like she had behaved out of character when it concerned her significant other, but the differences were subtle. It was much easier to not directly state what she had seen happen. It might be easier to carry a conversation

She was there to converse, but she didn't want to make him feel too uncomfortable.

"I think it's quite alright. Sometimes you do things you don't normally do. She must be really important."

The woman replied with a smile on her face as she disregarded the faint color in his face. It was better not to mention how flustered he looked right now. It did put the thought of Sephiroth being quite cute in her vocabulary.