Mixed tyre sizes

is this a bad idea?
i need a new rear and was thinking of trying a vittoria rad 700x28 on the rear but keeping the front as is which is 700x23.
is this going cause me problems or is it ok to run slightly wider tyres on the rear?

so long as there's clearance for the 28 it shouldn't cause any problems. People normally run the wider tyre on the front, not sure why though.

Last guy that tried this spontaneously combusted. Don't do it. Too many lives have been lost this year already..

i run a 35 on the rear and 28 on the front, it lulls when you lean into turns but you get used to it, there isn't a lot of difference between those two but it will feel light and slightly delayed on the front when you lean through a corner

i only stuck the 35 on the rear for polo and it handles lovely for quick turns

It should be ok but you may get AIDS, this is how greasy caught AIDS.

Just for thinking about it, the police will be knocking on your door soon. So sorry, goodbye.

ive already got aids but i am worried about spontaneously combusting and spreading it further

I think it's OK, as long as they are different colours. The front MUST be a primary colour though. Any other combo leads to AIDS.