Our Rugby Polygraph Examiner has conducted many infidelity lie detector tests over the years and deduced that cheating boyfriend behaviour is pretty much the same as cheating husband behaviour.

Cheating boyfriend behaviour

Naturally the following behavioural changes will only be recognisable if you have been in a relationship long enough to notice. When couples first get together it’s not uncommon for them to want to spend every spare minute in each other’s company.  However, as the newness wears couples begin to fall back into the type of routine they had before they met.  Friends that have been abandoned during the ‘honeymoon’ period come back on the scene. Hobbies that were swept aside reappear.  Nevertheless, in a committed relationship boyfriends will always make time for their significant other. So if he’s cheating he is likely to:

Spend more time with his ‘friends’

When you ask him who he was with he’ll invariably tell you that it’s no one you know.  If you show genuine interest in what he was doing, he will be vague about it and if pressed will accuse you of checking up on him.

Work longer hours

Despite spending extra hours at work he doesn’t seem to have any extra money.  Your sex life may suffer due to him being tired and ‘working’ so hard. There could be reasonable excuses for the above but it’s something to watch.

Cause arguments

It’s normal for couples to argue from time to time especially when mortgages, rents, work etc., get in the way of romance.  However, if he causes arguments over the least little thing it’s possibly cheating boyfriend behaviour.  Rows give him the opportunity to storm out of the house and not come back for a few hours.  Was he calming down or did he visit someone he is cheating with?

Be possessive with his phone

If he left his phone where you had access to it at the start of your relationship and now doesn’t that’s a sign he has something to hide.  Changing the password, taking or making calls out of your earshot, not answering calls, and getting calls late at night are all suspect.  Switching his phone off when he normally wouldn’t is also something to keep an eye on.


A classic sign of cheating boyfriend behaviour is gaslighting.  This means that he accuses you of something he is actually doing.  Attack is often thought to be the best form of defence.  If he is feeling guilty he’ll try to pass it off on you, especially if you accuse him of cheating.

Any or all of the above behaviours may have reasonable explanations but when more than one of them becomes the norm suspicion begins to develop.  Living with suspicion, sooner or later will become intolerable.

West Midlands Polygraph Service

If you think you are noticing cheating boyfriend behaviour and would like help, our Rugby Polygraph Examiner is available.  We have offices in most West Midlands main cities and towns and a free helpline for you to call (07572 748364).  Take advantage of it. An infidelity lie detector test is the quickest way to dispel doubt and move forward with your life.