I received a verbal offer from one company. They would like me to come back to them in 2-3 days (over the weekedn). I am finishing interviews with another. Those interviews won't finish for several days and the second company is my company of choice.

According to MT interview series (which I bought), the thing to do is simply ask for more time with the first company. Okay, I got that.

Should I be fully transparent and tell the first company I need more time because I am reviewing options with another company? I am all for being honest, but I think this case it is quite risky to do so.