Fabric softener composition comprising a betaine ester and a fatty co-softener

A fabric softener composition comprising:

• a. 1 to 20 wt. % ionic compound of general formula I:
• wherein
• A is a tetravalent linker selected from the group consisting of A-1 to A-6
• Q1 to Q4, which may be identical or different from each other, are selected from the group consisting of hydrogen, R and X, and W is an anion or an anionic group bearing w negative charges and r is the number of substituents Q1 to Q4 which are represented by a group X,
• wherein R, which may be the same or different at each occurrence, is a C5-C27 aliphatic group,
• m, m′, m″ and m′″, which may be the same or different at each occurrence, are 0, 1, 2 or 3,
• k, k′, k″, k′″ and k″″, which may be the same or different, are 0, 1, 2 or 3, and X, which may be the same or different at each occurrence, is represented by formula II
• wherein Z1, Z2 and Z3, are O, Y is a divalent C1-C6 aliphatic radical,
• R′, R″ and R′″, which may be the same or different, are hydrogen or a C1 to C4 alkyl group,
• the sum of n+n′ being 2,
• wherein at least one of Q1 to Q4 is represented by X and at least two of groups Q1 to Q4 are represented by R, which groups R may be the same or different at each occurrence, and
• wherein, if the ionic compound is such that (i) A is represented by A-6 with m, in, m′″ and m′″ equal to 0, (ii) one and only one of Q1 to Q4 is represented by a substituent X and n in the substituent X is equal to 0 and (iii) two and only two of Q1 to Q4 are represented by substituents R, then the difference of the number of carbon atoms of the two substituents R is 0, 1, 3 or more than 3,
• b. 0.1 to 20 wt, % fatty co-softener;
• and
• c. water.