Speaking from personal experience, I recently dated two at once.
This was because I was dating one and only been out once, with a few phone calls in between. I then received a phone call saying they had a ‘great match’ for me, but she would only be in town the following week so I had to see her while she was in town.
It was not by choice, but circumstances meant I ended up dating 2 girls at once, as I didn’t want to forgo that potential opportunity. I ended up seeing them in parallel for about 3 weeks and IMO it was difficult but doable to manage them separately – I had to make a conscious effort NOT to compare them and judge each one on their own merits, which is why it took 3 weeks for me to stop seeing one of them – as I didn’t want to stop seeing one just because there was another there, but rather based on whether I thought the potential with that person no longer existed – i.e. I had to be happy with my decision even if they both fell through, and not just making it because the other one was there.
Yes, it is difficult. Yes I DO NOT recommend doing what I did, but sometimes circumstances mean that it is sometimes necessary, not to miss out on a potential once-in-a-lifetime opportunity. If the same thing happened again, I would most likely do the same thing again, but alot of care was needed.
Though I didn’t do this completely alone – I told the shadchan who wanted to set me up with this great girl who was briefly in town that I just started seeing someone else, but she still said it was worthwhile to meet her….i.e. there are shadchans out there that given the right circumstances would not condone seeing 2 people at once.
Well that is my 2c anyway.