It is proper Netiquette to excuse yourself before use in group situations. Don’t use your phone while others are talking to you.
Interruption Netiquette Smartphones
Busy people need to check their smartphones sometimes, not all the time. When the time comes that a busy person needs to check their smartphone it is a great idea to let those your with know you will be busy for minute.
Excusing yourself is the same as telling your friends you will be right with them as soon as you finish a call, which is also good netiquette.
Excuse yourself to check devices because we may think your still engaged.
To smartphone rules.