Why would a guy that has boyfriend act like he likes one girl for months in front of his boyfriend?

[nonratracereality]

There is no easy way to dissect this but let's see. A reason a person does this is either because of insecurity issues with the relationship or the people or person or self involved. That said there is a reason or reasons but whatever they may be the person needs to advance their integrity maturity and responsibility in order to fortify their ability to love, require attention and to give back and ultimately necessary respect. If this happens is because their levels of maturity self esteem and future planning are low and need to be increased or advanced so this doesn't happen in the future.