Me and BrinkerzHD were looking for a way to do Unlimited Lives to make the CT Lvl 50 go faster and we found a way.
1st Get It To where you or your friend have Snd On CT.
2nd Have on person go to a Private Match after being in the lobby of CT Snd.
3rd Go to Game Options and hover over Unlimited Lives.
4th and important part. Have your friend invite you and when he dose once you are in the lobby with him have him leave so that you stay in that lobby. Dont mess with anything and start the game right away.
Tip. Me and Him were bypassed so im not sure if a friend on the 1.13 update can help you.
P.M. Me if you would like to join the lobby and get the unlimited lives.
Once you get the infection your friend has to do it also and then you kick them from the part so you both get more Xp.