They may look sexy, but they are a turn-off to your partner. S/he looks over to give you a “Hey, how about it?” look, and you miss it completely because you’re looking at . . . your device.
I am told by men and women on a daily basis that they feel ignored/unseen/unheard because their partner is looking at his or her device — a lot, every day. They are missing the cues that couples (and people in general) need for communication that come from conversation, eye contact, gestures, touch, and so.
Online content can be interesting (and of course the irony of this being online does not escape me), but the truth is that we need human contact and interaction.
Neuroscience shows that our brains are wired for this in order for us to thrive. (See Harlow’s study on monkeys for research, if that interests you.)