Have you experienced going on a date with your romantic partner and you have observed him looking at other ladies passing by? You told him that his actions offend you and though he seems apologetic, he just could not resist staring at persons of the opposite sex.
Should you really feel upset? Could this be a sign that he is losing interest to you? Not necessarily. It is normal to ogle with other people; it is our way of appreciation. However, your partner could have been a bit more respectful not to do so in front of you.
Also, if your date keeps on looking at other women that walks by and ignores you completely in the process, then there is a problem in your relationship. There is a fine line between ogling and flirting; you and your partner should discuss in matter in a non-confrontational manner. However, do not expect that he would stop cold turkey for you.
You can also try doing the exact same thing your partner is doing: look at other guys the same way your partner does. If he reacts, simply respond just like how he would normally respond to you. This could raise awareness to your partner that he should do his best to change his behavior. However, if he continues to do so, then there is a compatibility issue between the two of you and it may give you time to reconsider this relationship.