Husband going into bathroom to masturbate

So I get I'm 9 months pregnant, and not in the best shape. We still have sex but itd uncomfortable. But tonight he didn't even try with me, he just grabbed his phone and went to the bathroom and jerked off, and lied about it.

My feelings are kind of hurt and I'm kind of angry but at the same time I suppose I don't blame him. . How should I feel ? Will this become a habit?