Lack of intimacy making me want to flirt

[MartinM40]

Im a married 40 year old guy, my wife recently got pregnant which were very happy about. but she's often tired or not feeling well, so we dont have much sex. She's also not that adventurous in bed. I dont like to raise it with her, cos she does her best and I dont want her to feel bad. but the problem is, i often get so horny particularly during the day, and I end up eyeing off every woman that comes along, and looking for opportunities to flirt. and i have also been sexting with another married woman, has been pretty intense, but we have no intention of actually meeting up or cheating physically (we dont live anywhere near each other anyway). I feel bad that im cheating on my wife, but the other half of me really enjoys the thrill, and it does help to spice it up when we do have sex. is it wrong to keep doing this, or is there a better way to resolve the dilemma?