Would you be concerned?

I see that my husband keeps getting text messages late at night, 6pm-1am. Sometimes even til 6am. Yesterday it was his bday, we went out to do errands, nd also took our son to the hospital. I saw that he kept txting someone. He even did it while driving. i ask why he keep txting and who it is, for him to look out the road. He got upset, never answered my question. We got home and he stayed in the garage for an hr. Smoking and drinking. While touching his phone. Txting that person.