I was in a previous relationship in which my partner would be on the phone or on the laptop quite a lot. I just looked at it as their thing, habit and behaviour and found it harmless. But then it became apparent that they were talking to their male friend, all the time. Being me I said nothing, because I am cautious about coming across as over bearing or possessive. In the end she dumped me for him. But I guess it's different for all. I would add though, that if they are always on the phone it is kind of suspicious, as even business types need to save on minutes.