There are few real cases where that "because" fits the sentence snugly. In the details, the querent switches off to "involved", which is totally fair, just, and common. So, let's go with "How does it feel when your girlfriend is involved with your job loss?" for now, and see what happens…
Okay, for me, I could honestly say this has sorta happened to me three times:
- I dropped out of college due to massive, sudden, unexpected heartbreak;
- I lost a chance at a promotion from IT into Internet Marketing, after a brief fling with the company webmaster (those late night website launches, argh!); and
- I lost my job due to a general executive team sweep, and then so did my coworker/subordinate, who was supposed to take my role in the interim, but was then falsely rumored to be my "girlfriend" – had to go for "security reasons". That one was the worst!
These situations may not map directly to your own. Heck, every situation is going to be very different, and seem very personal to you. The thing is, though, to the company, "none of it is personal".
This is in part why so many companies have rules or guidelines against in-house fraternization among staff (sometimes explicit, sometimes just overextended sexual harassment policies)… Basically, it just adds a layer outside the control hierarchy, a layer which can only affect the company in bad ways.
Sometimes that means a bad breakup plus a girlfriend/boyfriend with leverage means you get the boot… Sometimes it means you can't hire the best person for the job because you share matching rings and a last name. But it's just business. Bad business, maybe, but just business.
So, back to feelings. Basically, it sucks to lose your job for any reason. But it really sucks when you perceive the reasons to be something other than your work performance. But it's important to note – it may just be your perception. Those late night marathon sexcapades at the office may make you re-energized and excited to come into work the next morning, but someone has to pay the janitorial bills, and who's to say that your actual work results are improving?
Even if you're doing everything in your role with the company right, you're still massively screwing up in their eyes by not seeking romance elsewhere – I mean, I get it, with all the hours they expect us to work, who has free time to meet new people outside work… But still, being able to effectively keep things "all business" is hard enough with budgetary infighting and even who-gets-which-desks-after-the-move type office politics. Adding hormones and genetalia to the party doesn't always make it more fun for the guests[*].
So, I guess my point is, whatever the reason, but especially when love and sex are involved, you simply need to let go. When you're fired, the "why?" is infinitesimally less important than the "what next?" – and in this economy, trust me, you only have time to dwell on one. Best to host a real, physical funeral for your lost job, and mourn properly. A day, a week at most, and then right back on the horse. Otherwise, you'll wind up penniless and jobless after a two and a half year job hunt, like me… Answering questions on Quora while listening to the rain drip in through the hole in the roof that you can't afford to fix.
[* But please, tell me where those parties are, and I'll do my best to help. ]